Nozzle assemblies are used in a variety of applications, and for several applications the performance of the nozzle assembly is related to the amount of fluid entrained into the fluid being ejected through the nozzle assembly. Typically, nozzle assemblies that attempt to incorporate entrainment properties are utilized in fluid mediums where turbulence exists and entrainment of a fluid surrounding the nozzle into the ejected fluid is desired. Additionally, nozzle assemblies incorporating entrainment properties are utilized in fluid mediums where uniform entrainment of a first fluid surrounding the nozzle into the path of an ejected second fluid is desired.
For purposes of clarity, fluid, as used herein, is intended to encompass any medium which may be emitted through the nozzle opening including, but not limited to, gases, foams, mists, air, steam and the like.
Various nozzle assemblies requiring entrainment and/or mixing of one fluid surrounding the nozzle assembly with another fluid ejected through the nozzle assembly may be included with products such as submersible dredging tools for clearing away material beneath a body of water; underwater cutting apparatus utilizing a jet-like fluid cutting medium; pre-mix combustion devices; hydrotherapy jet assemblies; flow-amplifying liquid atomizing nozzle assemblies; underwater jet assembly cleaning tools for pools, ships and/or offshore drilling rigs; pumping ejectors; fluid mixing devices; and, subterranean drilling tools utilizing nozzles.
In fluid mixing devices where entrainment and mixing properties are required to integrate a first fluid surrounding the nozzle assembly with a second fluid ejected through the nozzle assembly downstream of the nozzle assembly, various shaped nozzle openings and internally contoured nozzle bores or throats have been utilized without regard to the contour of the nozzle assembly's external surface. For example, U.S. Pat. No. 4,519,423 to Ho et al, is an apparatus for mixing fluids that includes a first fluid conductive means terminating in at least one non-circular orifice for emitting a jet of first fluid along a path in a pre-selected direction, and a means for providing a second fluid at a location downstream of the orifice for mixing with the first fluid. In a preferred embodiment, the orifice is elliptical to generate a jet of non-circular cross-section and relatively low aspect ratio. Thus, Ho primarily deals with various jet orifices for emitting a first fluid to enhance mixing with a second fluid downstream from the orifice. And, U.S. Pat. No. 4,957,242 to Schadow et al is also directed to a fluid mixing device in which a jet of first fluid is passed through a nozzle having a conical inlet section and a non-circular elongated exit section. The jet of first fluid mixes with the second fluid located downstream of the device. The interaction of the conical and elongated sections produces axial rotation in the first fluid causing it to mix with the second fluid.
Another application requiring entrainment properties deals with drilling tools where the evacuation of swarth and drilling cuttings is desired. For example, U.S. Pat. No. 3,358,783 to Raynal et al discloses a rotatable drilling tool that includes areas without cutting elements that are generally of a shape which become concave toward the top end and are set back with respect to the cutting areas to allow the evacuation of swarth and drilling cuttings toward the slotted parts on the periphery of the tool.
Additionally, underwater nozzle assemblies for use in hydrotherapy and cleaning applications have revealed a need to entrain the fluid surrounding the nozzle assembly with that being ejected through the nozzle itself. For example, U.S. Pat. No. 4,768,532 to Johnson discloses an underwater pool cleaner that utilizes water pressure to both vacuum and sweep the underwater surfaces of the swimming pool. A venturi restriction is created just forward of the thrust nozzle, creating a low pressure zone that induces flow of water through the bottom of the carriage, generating a vacuum that draws in leaves and other debris. U.S. Pat. No. 5,133,503 to Giordano et al discloses another type of swimming pool cleaning apparatus for cleaning submerged swimming pool surfaces with a direct pressurized and intensified water current. The device includes a nozzle assembly which can concentrate and intensify the water ejected from the assembly so that it can force a water current under the submerged swimming pool in the direction chosen. And, U.S. Pat. No. 4,731,887 to Henkin et al discloses a hydrotherapy jet assembly to discharge a high intensity stream of water into a tub without requiring air entrainment. Water drawn from the tub is entrained by the water jet to maintain the momentum of the water jet in order to produce an apparently high intensity stream for impacting against the user's body, compared to a stream without air entrainment.
Finally, various other applications involve the entrainment of a first fluid (air) surrounding the nozzle assembly's exterior surface into the path of an ejected second fluid in order to either dilute, mix or otherwise integrate the two fluids at a location downstream of the nozzle assembly. For example, U.S. Pat. No. 4,555,059 to Collins et al discloses a liquid atomizing nozzle in which intermixing of air and liquid occurs externally of the nozzle and the primary air utilized for such intermixing is amplified by the entrainment of ambient secondary air. Air under pressure is discharged through radial openings in the cylindrical section of the tubular nozzle body and is redirected by a collar surrounding the cylindrical section to form a high-velocity stream of air about and along the gradually tapered outer surface of the nose section. U.S. Pat. No. 5,518,395 to Maughan relates to fuel nozzles that employ an entrainment feature for initial partial premixing of gaseous fuel and air. Thus, a fuel nozzle assembly is provided comprising a fuel inlet means having a reduced cross-sectional area; a first air inlet means located adjacent to the reduced cross-sectional area; an expansion area having first and second ends such that the first end is located adjacent to the first air inlet means; a fuel and air outlet means located adjacent to the second end of said expansion area; a second air inlet means located adjacent to the fuel and air inlet means a fuel and air mixing means located adjacent to the fuel and air outlet means; and the second air inlet means; and a combustion chamber located adjacent to the swifter means for combusting the fuel and air.
It is therefore, apparent from the above that there exists a need in the art for a nozzle assembly that incorporates a housing adapted to receive a nozzle body, the housing having at least one or more indentations ideally contoured to permit a fluid surrounding each indentation to be entrained into another ejected fluid through the nozzle body in order to direct the integrated fluids therby, increasing the turbulence and velocity of the combined fluids downstream of the nozzle assembly.